Katopter



Oct. 13, 1931. F. MOFADDEN 1,827,250

KATOPTER Filed May 25, 1928 "mated-a}; 13, "193i o i TQ m f Application area m 25,3}1e2 8if serial jno; 250,603;

This invention relates to a katopterfor ape;

V plication to a phoropter or similar'measuring f p I I l have been; Vencountered'due to the Jreflected,

lightrbeing provided through {the identical J o iinstrurnentp The principal Iightbeing projected through identicallenses employedin the eye measuring instrument and receiving-the 'light fromzthe skiascop'e held in-the hand oftheuserand especially to m: provide a construction'in' which the annoya-ncet-and difliculty offmaking estimates when cases; and .to providea constructionfilr vvh-ich light from a suitable source 'isvreflected; i-n'to{ the eye' of the patient and the direction'ade' 'justed without passing through the jlensesof the measuring instrumentand without'losing itsefi'ect or obscuring the efYeCtpfJthemeaSQ uring instrument itselfQ After such a' Fbeamof'light falls on the eyeof the patient it is re M transmitted hythe;- optical "properties of the eye, thence; falling-upon the [observation 1 or I measurement lenses, from thelfarthersideof which lenses it p'rhceeds to the eye of the ex;-

tion'will appear hereinafter.

i *Reference istof be had'to theaceompany I ing drawings-in which 4 'bodiment of, my ka topter 'shovvn 'sectionas applied'thereto';

- 7 Fig.2 i a sectional view o the'line of Fig-1'; Fig;. 3 is a horizontal sectiona 1 I 'L3Qf i l";

thekatoptegandrg a y 1,

' Fig. 5 is afperspective view of a" detail;

obi'ectsof ithe invention to avoid the difficulties due to'thereflected Other obj cts-and advantages oi thein venQ v c a a y 'ment; 1 V H -1 rt'f nr. I

b a de -Q r d ,,a-

I-haveshovvnmy invention as applied to a measurlng instrument with a preferred em- C n ra 'l -ieretoifjore in: the use ofz the. usual measur I ingiinstruments for the eye, many difiiculties lensused intheieye 1e1'1s'es,this lensv receiving light from the instrumentheld in the hand of f -the,user.;. e These;lensesreceive the light from 1 I the "front .andl for'in'stron'g reflectors inthe' T front and-rear surfaces. Partjicularlywvhen several-such measurement lense'sfiare em- 7 v ployedthe' number ofrefiectionsbecomes very; x annoylngx and ohkewlsema' ke' fiheestimates With measurement lenses exceedingly difficult; or impossible; .rflhis isdue tothe factthatthe intensive brilliant points of reflected: light far; 6

'exceedrthe luminositytof thatfof tlie illuihi'nation uponfthesz retina.

Inhi'gh? myopic on hyperopic zcasesstrong measurement 'lenses arej-necessaryl Their high power dueftotheir curvature as Well as I their-vg reatr ,dispersal or wastingipowery of 7 lightiblock the 'entire procedure in this class of lenses. a Therefore the instrument is a re'njdered-practically useless and it is'l necessary to revert to primitive methodsiinasuch cases.

Itrjis" "alsotrue that theiprojected light 1 from-*the skiasc'ope isfmodified to a greatextent: in} its passage;through themeasuringv lenses 38." "This entrant modificationfofthe projected rbeam; is detrimental to accuracy a in proportion to? the strength or powerof the lensesi'; 1N iththe'present'invention'the.en trant beamfdoes'not pass through the meas-i v urin'g lenses asjheretofore but goes into the examined eye fromhehind themnTherefore 3 I no othermodificationfof the entrantbeam willj be present ,upon o the examined retina thanilisintended'rby theiprojecting' instru-* .measuring instrument 10',Iit-being;.under stood ;that" it is adaptable, to; measuring "in-" "strumentsiof'thisfgeneral character. It can he built/into themachine and constitute part"- u of itgorapplied. to it asran attachment, as odesired i-g o. 1 v o j-I nfits preferrediorm ittcomprises a main o a g- 4 is si v -l h re e es d f frame ll attache'dor securedto the me'asur special electric lamp mounted in a housing 13 rotatably mounted on a flange 14 at the end of the casing 11 and adapted to be held against rocking axially thereon by a concave cylindrical flexible Washer 15 fixed to the housing and the housing is secured in position by a SGI'BYV16L- ll his housing is adapted to be turned by a handle 17 on its lon'gfituidinal aXis and has a pointer 18 for showing.

on a scale 19 its position. The scale is located on an extension 20 on the-casing'l l. Thehan dle 17 is used to turn the housing 13 and point.

located inside: the. casing 11: to complete the passage ed a beam of. light to a lens located: in a focusing. tube 23. This tubeis adapted: to slide along the. casing 11. being operated by: handle which projects througha slot.

; inthis casing. It isa dapted .toa-behe'ldi in adjusted. position bythunrh screw- 261 and is adapted to be forced. against: a spring. 2:] which: will hold: the" tube in; aidjustm'entand cause it to be tiltedcas the: operator sire- The position of the: tube 23=isi read on a: scale 28: by means 0t apointen29 on the: handle2 l. .-J f g The lightfirom' thelamp12' passes through the: lens 22. and is reflected by an o bj eetive mirro r' 30 which is p ivotedi so that its: angular positmnacani be adq ustedby ascrew 3'1. Light 1s" their reflected; through an: ocular 1111121'01132 into the eye E ot the patient.- it willbeun derstood that the: operation is looking along.

the line: 333'3 into the eye ot the: patient.

This mirror .32: is mounted: on: a slide. 345 guide-ct vertically in: the present instance and operated? by alever 35 Link 36 andhand lever ST-piVotedon the body 11;. In its working 1 positionlthe. top'of this mirror comes just to the-f. line. along which the operator." looks into the eyeot. the patient. The object in:- turni'ngjthel housing 1'3and the lamp 12 therein is to change the angle ..-i of this lamp which may have: astraight line filainentor one of a U -sha-ped construction andtlrusz change the shape of the: beam: 0t light reaching the eye; This: permits of? several tests, as willube obvious: to any person skilled: in the art. The motion of: the tube 28 longitudinally is for the purpose oil fiocus= the lens-32 on. a desiredxpoint'and this tube is? mounted to: move laterally to a slight degreerto change the direction.

In the use of the instrument the operator looks into the patients eye along the central line 33-33 and through any number of lenses 38 that may be required. The eye is illuminated by the lamp 12 by throwing a straight beam into it or one of any desired shape which can be controlled by the shape 0t thevlamp filament and the-position of the la inpi in its" housing 1 3. as. indicated on the scale 19...

It will be seen that the reflected light thi'ou'gl'i the" lenses" 38 through which the operator observes the eye is cut oil, the several reflections thus encountered in the prior 7 practice are auoided. and the estimates or measurements are much less diilicult than has been the case: heretotore; Furtherm'oiie in higlnmyopic and hyperepic cases the: strong. lenses required do not affect the: tocalization character of the: entrant beam; before" enfleeing theey'e of the: patientand the ineasu instrument can be used in many sueir cases Where it was irnpossi ble before.

Ans has been pointedv out above the mac-- curacy dueatothe modification of projected beams from the-skiascope ispractically' slimr inated. The: several parts can: be regulated in a simple and convenient man-lien, colored glasses can-be inserted: where required. and in iiact the: instrument is capable: of modification by ordinary Well-known; me artsto secure all: the effects that. may be desired in this class of testing. The; ocular mirror can. be raised out of. the: way, out. of the range of. the examined eyewhen not? being used.

have. described particularly the mechanism.

for: accomplishing that result- 'Although. I have illustrated and described only one formot theainivention I amvaware of. the fact that modifications. can? be made therein by person skilled in thear't with out. departing from the: scope out the invention as. expressed in. the claims. Therefore, I (lo-not WdShtG- bG limited in these. repeats. But. what I do elaimi is c.

1. In device-- on. the-"character" described, the combination with a trame-and asou'rce' of light located; therein,'. eat a focusing tube said. traine having a lens through. which thelight from the source passes, means for: movthe tube forward and back, means for tilting it to change itsidireetionl and mirrors for reflecting theliight. into'the eye of. the patient.

2. In a device for attachment to. a. measuringinstrument, the combination with a frame connected with the measuring; instrument, a

source of light carried by the frame, a lensi'or directing the beam of light therefrom, a ivotalmirroi; in said frame'for'receivingthe eam oflight, means for adjusting themirror about its pivot and a second mirror arranged at the hack of the measuring instrument for directing the beam of lightfrom thelirst mirror into the eye of the patient.

' 3. In a device for attachment toameaisur ing instrument, the combination with a lira-1n! i the s I the frame at the point where the horizontal adapted to he located on the measuring instruinent and provided with a horizontal and i vertical hollow portion, a reflecting mirror at the top of the vertical portion and'outside it and located slightly out of line from the lenses of the measuring instrument, a source of li ht carried inside thehorizontal part of Frame, a slanting mirror carried within and vertical parts join for directing light from the source of light to -the first named mirror and into the eye of the patient.

4. In an instrument of the chara'cter described, the combination with a casing having a main or horizontal part and a transverse 'part, both partsbeing hollow, of a lamp housing rotatably mounted on the open end of the horizontal part of the casing, a source of light carried by} said housing, a lens in the path of the rays o'f light from said source, a

mirror carried by the casing onits transverse part for reflecting the light into the eye of the patient,'a slanting mirror for, reflecting the light fromthe lens to the first named mirror aninside tube supporting said lens and 'f j ing Said'tube laterally. to change the angl f th -1 V e r In testimony whereof'I have hereunto affixed my signature. j I I I Y MOFAVDDEN; H 

